Thermoresponsive Starch Hydrogel Stabilized Pd Nanoparticles: Soft Catalyst for the Preparation of (±)-α-Methylbiphenylalanine in Water Aiming at Bioorthogonal Chemistries

The corn-starch was able to reduce Pd(II) species under relatively low concentration (5.0 wt/vol) leading to the formation of a thermoresponsive palladium nanoparticles-containing hydrogel with D = 16.1 nm +/- 6.4 nm. It was successfully applied to the Suzuki-Miyaura reaction step in neat water involved in the synthesis of (+/-)-N-acetyl-alpha-methyl-4-biphenylalanine ethyl ester, a direct precursor of an unnatural quaternary biarylalanine. [GRAPHICS] .

Automated summary

Corn-starch was used to reduce Pd(II) species and form a thermoresponsive palladium nanoparticles-containing hydrogel with an average size of 16.1 nm +/- 6.4 nm. It was successfully applied in a Suzuki-Miyaura reaction in water for the synthesis of a precursor of an unnatural quaternary biarylalanine.